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About Our Research

Physics and Chemistry of Polymers.

Our research is focused on the design and characterization of functional polymer films. Our work can be applied to semiconductor device manufacturing, membranes, coatings, and low-cost plastic electronics. The following paragraphs introduce several core thrusts in our group.

Projection Lithography.

We are studying polymer imaging materials for optical lithography, which is the patterning technique used to define microelectronics circuitry. The goals of this program are to measure the chemical reactions that generate the images, build process models that incorporate ultra-thin film properties, and develop high-throughput screening methods for new materials.


We are studying block copolymer self-assembly for applications in low-cost nanopatterning of semiconductor devices. The goal of this research effort is to control self-assembly in three-dimensions by tuning interactions at the free surface and substrate interfaces.

Solar Cells.

We are studying the variables that control power-conversion efficiency in polymer-based solar cells. We build model devices for fundamental studies of photocurrent generation using top-down lithography. Ultimately, our goal is to improve the device efficiency by controlling the active layer morphology.

Thin Film Physics.

We have several ongoing projects that focus on the fundamental physics of thin polymer films. These studies include directed dewetting, suppressing phase separation in blends, self-healing films, and anti-fouling coatings.

Recent News

November 2015
  • Gila joins the Editorial Advisory Board of ACS Macro Letters and Macromolecules.

September 2015
  • Nikki and Indranil publish work on defectivity in perpendicular lamellar phases.

August 2015
  • Andrew Ma joins the group. Welcome!
  • Collaboration with Tang group is published.

July 2015
  • Abhijit and Indranil accept positions at Applied Materials and Intel, respectively. Congrats!

June 2015
  • Gila is an invited speaker at ISPAC 2015.
  • Gila is an invited speaker at Telluride Polymer Physics.

May 2015
  • Abhijit and Indranil complete their dissertation defenses. Congrats!
  • Mukund Kabra returns for summer research (REU). Welcome back!
  • Clint Kirchhoff and Paul Gallego join the group as undergraduate research associates. Welcome!
  • Gila is a plenary speaker at PolyChar23.
  • Indranil and Nikki publish work on block copolymer self assembly.


Dr. Gila Stein

  • Associate Professor of Chemical & Biomolecular Engineering, 2015-Present.
  • Joint appointments with the Chemistry Department and Materials Program, 2012-Present.
  • Ernest J. and Barbara M. Henley Assistant Professor of Chemical & Biomolecular Engineering, 2009-2015.
  • NRC-NIST Postdoctoral Fellow, 2007-2008
  • Ph.D. Chemical Engineering, University of California, Santa Barbara, 2006
  • B.S. Chemical Engineering, Drexel University, 2002

E-mail: gestein "at sign"

Graduate Students

Adeline Mah

  • B.S. Chemistry, University of Houston, December 2012
  • Research Interests: Lithography, surface chemistry, biosensors
  • E-mail: huizhen89 "at sign"

Minnie Lahoti

  • B.S. Chemical Engineering, University of Alabama, May 2014
  • Research Interests: Semiconductor lithography, reaction-diffusion models.
  • E-mail: minnielahoti "at sign"

David Truong

  • B.S. Chemical Engineering, Clemson University, May 2013
  • Research Interests: Block copolymers, membranes.
  • E-mail: pvtruong29 "at sign"

Saeed Ahmadi Vaselabadi

  • B.S. Chemical Engineering, Sharif University of Technology, Tehran, Iran, 2012
  • Research Interests: Organic photovoltaics, nanopatterning.
  • E-mail: sahmadivaselabadi "at sign"

Current UH Undergraduate Students

  1. Kokila Jayasekera
  2. Paul Gallego
  3. Clint Kirchhoff
  4. Andrew Ma

UH Undergraduate Alumni

  1. Thao Dinh, B.S. Chemical Engineering, May 2011
  2. Thai Vu, B.S. Chemical Engineering, May 2011
  3. Trang Pham, B.S. Chemical Engineering, December 2011
  4. Gus Rajaendran, B.S. Chemical Engineering, May 2012
  5. Loc Ngo, B.S. Chemical Engineering, May 2012
  6. Adeline Mah, B.S. Chemistry, December 2012
  7. Sean Hensarling, B.S. Chemical Engineering, May 2013
  8. Xidong Lin, B.S. Chemistry, May 2014
  9. Xiao Li, B.S. Chemical Engineering (ECUST), May 2015
  10. Pantea Afzali, B.S. Chemical Engineering, Dec 2015 (expected)
  11. Hanh Phan, B.S. Chemical Engineering, May 2017 (expected)
  12. Salima Charania, B.S. Chemical Engineering, May 2016 (expected)

REU Alumni

  1. Makenzie Dixon, Trinity University, Summer 2009
  2. Amara Enemuo, City College of New York, Summer 2009
  3. Leslie Scrof, Louisiana State University, Summer 2010
  4. Alona Bozhchenko, Rice, Summer 2011
  5. Mukund Kabra, University of Minnesota, Summer 2015

UH Graduate Alumni

  1. Dr. Suchanun Moungthai, Ph.D. Chemical Engineering, August 2012. (Intel)
  2. Dr. Ginusha Perera, Ph.D. Chemical Engineering, December 2012. (Intel)
  3. Dr. Nikhila Mahadevapuram, Ph.D. Chemical Engineering, May 2014. (Intel)
  4. Dr. Indranil Mitra, Ph.D. Chemical Engineering, May 2015. (Intel)
  5. Dr. Abhijit Patil, Ph.D. Chemical Engineering, May 2015. (Applied Materials)


  1. Akil Chittaluru, Klein Oak High School, Summer 2011
  2. Steven Tsai, St. Mark's School of Texas, Summer 2012
  3. Mukund Kabra, Colleyville Heritage High School, Summer 2013

The Lab

Facility & Equipment

  • 1,400 square feet of newly renovated lab space
  • Three chemical fume hoods
  • J.A. Woolam M-2000 spectroscopic ellipsometer with focusing optics and Instec heat stage
  • Nikon LV150 reflected light microscope (BF/DF) with digital camera
  • Brewer CEE 200CB spin coater and bake plate
  • Dataphysics OCA 15EC contact angle goniometer
  • Keithly 2601A source measure unit
  • HE-453-2 Vacuum Atmospheres glove box equipped with SCS spin coater
  • Oriel 150W solar simulator
  • Two VWR vacuum ovens
Other Resources


Journal Articles
  1. N. Mahadevapuram,* I. Mitra,* A. Bozhchenko, J. Strzalka, G.E. Stein, ``In-plane and out-of-plane defectivity in thin films of lamellar block copolymers,'' Journal of Polymer Science Part B: Polymer Physics, In Press, 2015. [DOI]
    • *Equal Contribution.
  2. J. Hayat, I. Mitra, Y. Qiao, G.E. Stein, C. Tang, ``Improving humidity-controlled solvent annealing processes for block copolymer poly(ethylene oxide)-b-polystyrene,'' European Polymer Journal, 71, 476-489, 2015. [DOI]
  3. I. Mitra, N. Mahadevapuram, J. Strzalka, G.E. Stein, ``Tilting of lamellar domains on neutral random copolymer brushes,'' Advances in Patterning Materials and Processes XXXII: Proceedings of the SPIE, 942320, 2015. [DOI]
  4. R. Verduzco, X. Li, S.L. Pesek, G.E. Stein, ``Applications and self-assembly of bottlebrush copolymers,'' Chemical Society Reviews, 44, 2405-2420, 2015. [DOI]
  5. G.E. Stein, N. Mahadevapuram, I. Mitra, ``Controlling interfacial interactions for directed self assembly of block copolymers,'' Journal of Polymer Science Part B: Polymer Physics, 53, 96-102, 2015. [DOI]
  6. 2014
  7. A.A. Patil, Y.N. Pandey, M. Doxastakis, G.E. Stein, ``Characterizing acid diffusion lengths in chemically amplified resists from measurements of deprotection kinetics,'' Journal of Micro/Nanolithography, MEMS, and MOEMS, 13, 043017, 2014. [DOI]
  8. G. Deng, Y. Zhang, C. Ye, Z. Qiang, G.E. Stein, K.A. Cavicchi, B.D. Vogt, ``Bicontinuous mesoporous carbon thin film via an order-order transition," Chemical Communications, 50, 12684-12687, 2014. [DOI]
  9. Y. Qiao, R. Ferebee, B. Lee, I. Mitra, N.A. Lynd, J. Hayat, G.E. Stein, M.R. Bockstaller, C. Tang, ``Symmetric poly(ethylene oxide-b-styrene-b-isoprene) triblock copolymers: Synthesis, characterization and self-assembly in bulk and thin film,'' Macromolecules, 47, 6373-6381, 2014. [DOI]
  10. I. Mitra,* X. Li,* S.L. Pesek, B. Makarenko, B.D. Lokitz, D. Uhrig, J.F. Ankner, R. Verduzco, G.E. Stein, ``Thin film phase behavior of bottlebrush/linear polymer blends,'' Macromolecules, 47, 5269-5276, 2014. [DOI]
    • *Equal Contribution.
  11. A.A. Patil, M. Doxastakis, G.E. Stein, ``Modeling acid transport in chemically amplified resist films,'' Advances in Patterning Materials and Processes XXXI: Proceedings of the SPIE, 90511M, 2014. [DOI]
  12. Z. Qiang, L. Zhang, G.E. Stein, K. Cavicchi, B.D. Vogt, ``Unidirectional alignment of block copolymer films induced by expansion of a permeable elastomer during solvent vapor annealing,'' Macromolecules, 47, 1109-1116, 2014. [DOI]
  13. J. Cushen, L. Wan, G. Pandav, I. Mitra, G.E. Stein, V. Ganesan, R. Ruiz, C.G. Willson, C.J. Ellison, ``Inducing order in poly(trimethylsilyl styrene-b-D,L-lactide) by solvent annealing using a mixture of domain-selective solvents,'' Journal of Polymer Science Part B: Polymer Physics, 52, 36-45, 2014. [DOI]
  14. 2013
  15. D. Sunday, M.R. Hammond, C. Wang, W.L. Wu, R.J. Kline, G.E. Stein, ``3D X-ray metrology for block copolymer lithography line-space patterns,'' Journal of Micro/Nanolithography, MEMS, and MOEMS, 12, 031103, 2013. [DOI]
  16. Z. Qiang, J. Xue, G.E. Stein, K.A. Cavicchi, B.D. Vogt, ``Control of ordering and structure in soft templated mesoporous carbon films by use of selective solvent additives,'' Langmuir, 29, 8703-8712, 2013. [DOI]
  17. E. Cacao, T. Sherlock, A. Nasrullah, S. Kemper, J. Knoop, K. Kourentzi, P. Ruchhoeft, G.E. Stein, R.L. Atmar, R.C. Willson,``Helium beam shadowing for high spatial resolution patterning of antibodies on microstructured diagnostic surfaces,'' Biointerphases, 8, 1-10, 2013. [DOI]
  18. E.E. Cacao, A. Nasrullah, T. Sherlock, S. Kemper, K. Kourentzi, P. Ruchhoeft, G.E. Stein, R.C. Willson, ``High-resolution, high-throughput, positive-tone patterning of poly(ethylene glycol) by helium beam exposure through stencil masks,'' PLoS ONE, 8, e56835, 2013. [DOI]
  19. M. Luo, J.E. Seppala, J.N.L. Albert, R.L. Lewis, III, N. Mahadevapuram, G.E. Stein, T.H. Epps, ``Manipulating nanoscale morphologies in cylinder-forming poly(styrene-b-isoprene-b-styrene) thin films using film thickness and substrate surface chemistry gradients,'' Macromolecules, 46, 1803-1811, 2013. [DOI]
  20. N. Mahadevapuram, J. Strzalka, G.E. Stein, ``Grazing-incidence transmission small angle X-ray scattering from thin films of block copolymers,'' Journal of Polymer Science Part B: Polymer Physics, 51, 602-610, 2013. [DOI]
  21. 2012
  22. G.M. Perera,* Y.N. Pandey,* A.A. Patil, G.E. Stein, M. Doxastakis, ``Reaction kinetics in acid-catalyzed deprotection of polymer films,'' The Journal of Physical Chemistry C, 114, 24706-24716, 2012. [DOI]
    • *Equal Contribution.
  23. G.M. Perera,* C. Wang,* M. Doxastakis, R.J. Kline, W.L. Wu, A.W. Bosse, G.E. Stein, ``Directed self-assembly of lamellar copolymers: Effects of interfacial interactions on domain shape,'' ACS Macro Letters, 1, 1244-1248, 2012. [DOI]
    • *Equal Contribution.
  24. S. Moungthai,* T.C.H. Pham,* A.A. Rajaendran,* G.E. Stein, ``Ordered arrays of polymer droplets with triangular, circular, and rod-like shapes,'' Soft Matter, 8, 10026-10031, 2012. [DOI]
    • *Equal Contribution.
  25. S. Moungthai,* N. Mahadevapuram,* P. Ruchhoeft, G.E. Stein, ``Direct patterning of conductive polymer domains for photovoltaic devices,'' ACS Applied Materials & Interfaces, 4, 4015-4023, 2012. [DOI]
    • *Equal Contribution.
  26. A. Labiano, M. Dai, W-S Young, G.E. Stein, K. Cavicchi, T. Epps, B.D. Vogt, ``Impact of homopolymer pore expander on the morphology of mesoporous carbon films using organic-organic self-assembly," The Journal of Physical Chemistry C, 116, 6038-6046, 2012. [DOI]
  27. 2011
  28. C. Wang, G.E. Stein, A.W. Bosse, W.L. Wu, ``Line edge roughness of directed self-assembly PS-PMMA block copolymers - A candidate for future lithography,'' AIP Conference Proceedings, 1395, 305-308, 2011. [DOI]
  29. T. Vu,* N. Mahadevapuram,* G.M. Perera, G.E. Stein, ``Controlling domain orientations in thin films of AB and ABA block copolymers,'' Macromolecules, 44, 6121-6127, 2011. [DOI]
    • *Equal Contribution.
  30. B.D. Vogt, V.L. Chavez, M. Dai, M.R. Croda Arreola, L. Song, D. Feng, D. Zhao, G.M. Perera, G.E. Stein, ``Impact of film thickness on the morphology of mesoporous carbon films using organic-organic self assembly,'' Langmuir, 27, 5607-5615, 2011. [DOI]
  31. 2010
  32. G.M. Perera, G.E. Stein, J.A. Liddle, ``Spatial coherence in electron-beam patterning,'' Journal of Vacuum Science & Technology B, 28, 1048-1055, 2010. [DOI]
  33. V. Mishra, S.-M. Hur, E.W. Cochran, G.E. Stein, G.H. Fredrickson, E.J. Kramer, ``Symmetry transition in thin films of diblock copolymer/homopolymer blends,'' Macromolecules, 43, 1942-1949, 2010. [DOI]
  34. G.E. Stein, J.A. Liddle, A.L. Aquila, E.M. Gullikson,``Measuring the structure of epitaxially assembled block copolymer domains with soft x-ray diffraction,'' Macromolecules, 43, 433-441, 2010. [DOI]
  35. 2005 - 2008
  36. C. Tang, J. Bang, G.E. Stein, G.H. Fredrickson, C.J. Hawker, E.J. Kramer, M. Sprung, J. Wang, ``Square packing and structural arrangement of ABC triblock copolymers in thin films,'' Macromolecules, 41, 4328-4339, 2008. [DOI]
  37. G.E. Stein, E.J. Kramer, X. Li, J. Wang, ``Thickness dependent ordering in laterally confined monolayers of spherical domain block copolymers,'' Macromolecules,  40, 5791-5800, 2007. [DOI]
  38. J. Bang, B.J. Kim, G.E. Stein, E.J. Kramer, C.J. Hawker, T.P. Russell, ``Effect of humidity on the ordering of PEO-based copolymer thin films,'' Macromolecules, 40, 7019-7025, 2007. [DOI]
  39. G.E. Stein, E.W. Cochran, K. Katsov, G.H. Fredrickson, E.J. Kramer, X. Li, J. Wang, ``Symmetry breaking of in-plane order in confined copolymer mesophases,'' Physical Review Letters, 98, 158302, 2007. [DOI]
  40. G.E. Stein, E.J. Kramer, X. Li, J. Wang, ``Layering transitions in thin films of spherical-domain block copolymers,'' Macromolecules, 40, 2453-2460, 2007. [DOI]
  41. G.E. Stein, E.J. Kramer, X. Li, J. Wang, ``Single crystal diffraction from two-dimensional block copolymer arrays,'' Physical Review Letters, 98, 086101, 2007.  [DOI] (Cover)
  42. V. Khanna, E. Cochran, A. Hexemer,  G.E. Stein, G.H. Fredrickson, E.J. Kramer, X. Li, J. Wang, S.F. Hahn, ``Effect of chain architecture and surface energies on the ordering behavior of lamellar and cylinder forming block copolymers,'' Macromolecules, 39, 9346-9356, 2006. [DOI]
  43. A. Hexemer, G.E. Stein, E.J. Kramer, S. Magonov, ``Block copolymer monolayer structure measured with scanning force microscopy moire patterns,'' Macromolecules, 38, 7083-7089, 2005. [DOI]

Book Chapters
  1. G.E. Stein, ``Scattering methods for thin polymer films,'' In Functional Polymer Films: Characterization and Applications, R. Advincula, W. Knoll, Eds.; Wiley-VCH: Weinheim, 2011, pp. 669-694.


Research Experiences for Undergraduates

The theme of our REU program is Innovations in Nanotechnology.


Girls Reaching And Demonstrating Excellence, Summer 2011

Materials Day

Participants from North Shore High School, January 2012

Mars Rover Day

Participants from Houston area middle schools, January 2012